1. Field of the Invention
This invention relates to a modular mandibular prosthesis for replacing a patient's mandible, which has been surgically removed, by forming an artificial mandible or part thereof.
2. Description of Related Art
Mandibular resection, or removal, due to disease has presented physicians with numerous difficulties in reconstructing the mandible, or lower jaw, to give the patient use of his remaining portion of mandible. Proper reconstruction of the mandible includes providing the patient with a natural appearance and proper occlusion of the teeth of the mandible with the teeth of the maxilla, or upper jawbone. It is also desirable to enhance the physician's reconstruction of the mandible using a prosthesis which is easy to install and customize, thereby decreasing the length of time the patient is in surgery.
Prior approaches to replace the portion of the mandible which has been removed include implanting a mandibular prosthesis made out of a plastic, such as an acrylic plastic material, or some other suitable metallic material, such as titanium. The mandibular prosthesis may be attached to the remaining portion of the mandible using various techniques. In one approach, the prosthesis is attached to the mandible using a male coupler and a female coupler which are interlocked with one another. In another approach, a titanium plate is preformed, or bent, to the approximate shape desired to secure the prosthesis across the gap in the mandible created by the resection. In still another approach, the prosthesis is constructed out of mesh and tubular components attached to the mandible. All of these approachs have deficiencies. Most notably, all of these approachs require increased planning time because the prosthesis must be preformed, or molded, prior to surgery. Prior to the operation, the physician approximates the contour of the mandible and approachs to anticipate the shape the mandibular prosthesis must take to function properly. Accordingly, precise calculations and adjustments must be made to the mandibular prosthesis prior to beginning the operation. Should the pre-operation steps of shaping the mandibular prosthesis not be correct, the mandibular prosthesis will have to be readjusted, or in some cases, a new mandibular prosthesis will need to be shaped, before the mandibular prosthesis can be implanted.
Another deficiency is the inability of these prior approachs to be easily and quickly modified, or customized, during surgery. Should the mandibular prosthesis be attached to the mandible when the fit is not precise, these prior approachs do not allow for easy modification and customization of the mandibular prosthesis. Accordingly, should unforeseen circumstances render the pre-formed prosthesis unworkable, a new prosthesis will be required, causing delay and increased surgery time. A new prosthesis may also be required should the physician find it necessary to remove more of the patient's mandible during the operation than was originally planned due to undetected spreading of the disease.
Accordingly, prior to the development of the present invention, there has been no mandibular 10 prosthesis which: allows for easy readjustment while the mandibular prosthesis is in place; allows easy modification due to unforeseen circumstances; obtains more accurate occlusion without planning in a single rapid step; eliminates plate bending; decreases operating time; and improves the shape of the mandibular prosthesis to reduce any damage which may be caused by the placement of the mandibular prosthesis. Therefore, the art has sought a mandibular prosthesis which: allows for easy readjustment while the mandibular prosthesis is in place; allows easy modification due to unforeseen circumstances; obtains more accurate occlusion without planning in a single rapid step; eliminates plate bending; decreases operating time; and improves the shape of the mandibular prosthesis to reduce any damage which may be caused by the placement of the mandibular prosthesis. It is believed that the present invention will achieve these objectives and overcome the disadvantages of other devices in the field of the invention, but its results or effects are still dependent upon the skill and training of the operator.